Effects of vertical fault fracture zones on the spreading of Rayleigh wave and ground motion

Dynamic time history analysis of ground motion with vertical fault fracture zones of different widths and shear wave velocities under Rayleigh wave was carried out by using the Rayleigh wave input method based on the viscous-spring artificial boundary. Influence of vertical fault fracture zones with various widths and shear wave velocities on the spreading of Rayleigh wave and ground motion was investigated. The results show variations of fault width and shear wave velocity have little effect in the mediate and far field on the incident side. Peak displacement response of the fault corner and the ground nearby on the incident side enlarges greatly with the increase of fault width or with the decrease of shear wave velocity of the fault. While in the mediate and far field on the other side, peak horizontal and vertical absolute displacements decrease gradually with the increase of fault width or with the decrease of shear wave velocity of the fault, and the horizontal displacement peak has a slighly decrease than that of vertical displacement peak. The results indicate the weak fault fracture zone weakens the Rayleigh wave and with the increase of fault width or with the decrease of shear wave velocity of the fault the weakening effect tends to be enhanced.